Carbonization of cellulose esters



Patented June 23, 1942 CARBONIZATION OF CELLULOSE ESTERS Charles Franklin Miller, Wilmington, DeL, as-

signor to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation ofDelaware No Drawing. Application March 2, 1940,

Serial No. 321,908

7 Claims. (CI. 41-41) This invention relates to a process for the carbonization or selective destruction of the cellulose ester portion of mixed goods, that is fabrics woven of more than one type of fiber but of which one component is acelluloseester.

It is an object of this invention to provide a simple and economical process for' the selective destruction of the cellulose ester component in a mixed fabric containing the same, whereby to produce local designs upon such fabric, of a lacy or voile character. It is a further object of this invention to provide a process for the removal of cellulose ester fiber from any mixture in which it may occur. Other and further important objects of this invention will appear as the description proceeds.

My invention is based on-the discovery that polyhydric phenols, particularly those phenols in which at least two of the hydroxyl groups are in meta position as typified by resorcinol,fhave theproperty of carbonizing, attacking, or otherwise reacting with cellulose ester fiber, rendering it brittle. If the phenol is employed insuflicient concentration, say 10% or over, the fiber may be made so brittle as to be capable of being.

vantage. 'Among these may be mentioned cathecol, quinol, orcinol, quinitol, pyrogallol, phloro- 'glucinol, hydroxyquinol, tetrahydroxy-benzene, 'pentahydroxy benzene, hexahydroxy benzene, and the various nitro, halogen and methyl derivatives of the above, including especially the nitro-resorcinols and the chloro-resorcinols.

The printing paste may containother reagents for producing various effects on the fiber, especsimply on the surface of a drum drier.

invention cona'water-soluble ,polyhydric phenol in a concern tration not less than 10%. Application to the fiber is best made in the form of a printing paste by. the usual printing procedures. After printing, the fabric is preferably. heated dry or aged with steam, the latter procedure being particularlydesirable where the printing paste contains additional ingredients, for instance dyestuffs, resists or discharging'agents, which are customarily developed by steam aging. After this step the fabric is dried and then subjected to mechanical work ng, for instance brushing, whereby the destroyed and crumbled cellulose ester fiber is ability, good solubility and general lack of hazard in handling, resorcinoris one of the preferred phenols for this invention. Other members of this series may, however, also be used to good adially dyestuffs and discharge agents. The latter of course are applied only to fabric which is dyed, while the former'may be applied to noncolored fabric, thereby introducing. a local color, or it maybe applied jointly with a discharge agent to a dyed fabric thereby producing a local color effect different from the ground color. Resists may also be added to the printing paste, in which case the printing step is followed bya-dyeing operation,

The heating or aging step may be performed in a rapid ager, cottage steamer, vat color ager, or

Where steam aging is preferred, it may be performed at elevated pressure or reduced pressure, as most convenient.

Without limiting my invention, the following specific examples are given to illustrate my preferred form of procedure. Parts mentioned are' by weight.

Example 1 A printing paste is made up as follows:

Parts Resorcinol 20.0- Water v, 20.0 I Gum tragacanth (6%)5 r l 60.0

Total Q 100.0

Print on mixed cellulose acetate-viscose piece goods; dry; steam for 10 minutes at '10 lbs. pressure in a cottage steamer; run through a brush ing machine such as is described in Textile Bleaching, Dyeing, Printing and Finishing Machinery-A. J. Hall, pages 114 to 118, whereby the cellulose acetateportion is removed as a dust, leaving a voile eifect in the printed portions.

Cellulose acetate-viscose mixed piece goods is printed and finished as in Example 1, giving the same voile effect.

- Example 3 A printing paste is made up as follows:

' Parts Resorcinol 15.0 Bentonite 15.0 Water v I "70.0

Total 100.0

Cellulose acetate-viscose mixed piece goods is printed and finished as in Example 1, giving a The above printing paste is'printed on goods consisting of a mixture of cellulose acetate and viscose fibers and finished as in Example 1, giving Print and finish as in .Example 1, giving a voile effect in the printed areas of the fabric.

- Example 6 A printing paste is made up as follows:

' Parts Reser n 20.0 Sodium sulfoxylate formaldehyde 10.0 .Water 10.0 Gum tragacanth 60.0

'I'otal 1 100.0

The above-is printed on mixed goods containing a cellulose ester fiber, dyed with a dischargeable dye, for instance the disazo dye described in Color Index No. 317, and finished as in Example 1, giving a white voile design on a blue background.

As already mentioned, the mixed goods in the above examples may contain, beside the cellulose ester, fibers of silk, wool, Nylon, viscose-process rayon, copper-ammonium-process rayon, linen, or any combination of these.

Instead of cellulose acetate, in the above examples, cellulose formate, or any other ester of cellulose may be employed.

Instead of steaming this cloth for a short time under pressure, it may be steamed a longer period at low pressure, dried in a hot flue or even aged in a vat color ager.

Many other variations in detail will be apparent to those skilled in this art, without departvoile effect in the printed areas.

' Example 4 A printing paste is made up as follows:

. Parts Resor r 20.0 Anthraquinone acid color, Color Index No.

' Urea 15.0 Water v 13.0 Gum tragacanth (6%) 50.0

Total 100.0

ing from the spirit of this invention.

I claim:

1. A process for the selective destruction of the cellulose ester component of a mixed fabric containing cellulose ester fibers, which comprises treating the same with a polyhydroxy phenol.

2. A process of producing a fabric having local designs of a lacy or voile nature, which comprises treating a union fabric, of which one of the components is a cellulose ester, in local designs with a polyhydroxy phenol in sufiicient concentration to render the cellulose ester fibers brittle at the treated areas, and then subjecting the fabric to mechanical treatment to remove the brittle fibers.

3. A process of producing lacy or voile effects on union fabrics comprising cellulose ester fibers as one component, which comprises applying to the fabric locally a printing paste containing a polyhydroxy-phenol in concentration not less than 10% by weight of the paste. v

4. A process of producing local designs of lacy or voile character upon union fabrics containing a cellulose ester as one of the component fibers,

which comprises printing said fabric with a printing paste containing a polyhydroxy phenol in concentration not less than 10% by weight of the printing paste, then aging the fabric, drying it and subjecting the dried fabric to mechanical brushing whereby to remove brittle fibers in the areas treated with said printing paste.

1 5. A process as in claim 4, wherein the printing paste contains further a member selected from the group consisting of dyestuffs and discharging agents, whereby to modify the color of said local designs simultaneously with the destruction of the cellulose-ester component.

6. A process as in claim 4, the polyhydroxy phenol being a meta-dihydroxy phenol.

'7. A process as in claim 4, the polyhydroxy phenol being resorcinol.

CHARLES FRANKLIN MILLER. 

